1. Field of the Invention
The invention relates to a watercraft battery control system for monitoring a battery charge. The system informs the watercraft operator when the battery charge is below a predetermined value and automatically starts the engine to allow a generator to replenish the battery charge when the battery charge has fallen below a predetermined value.
2. Description of the Related Art
Watercraft (e.g., personal watercraft or boats) typically incorporate internal combustion engines along with propulsion units to provide power and propel the watercraft in a variety of popular applications. The internal combustion engines can operate according to the two-cycle (two-stroke) operating principle or the four-cycle (four-stroke) operating principle. Outboard motors are being manufactured in larger sizes to meet higher power demands from watercraft operators. The cranking torques required to start these large displacement engines, especially four-cycle engines, have become too large to allow such engines to be started by hand. Cold weather also increases engine-starting torque by affecting the viscosity of the lubricating oil. A high torque starter motor that receives electrical power from a battery is therefore necessary to start the watercraft engines.
A battery is essential for operating the watercraft, and since the amount of power consumed is larger for a starter than for the other electrical components, the remaining charge of the battery needs to be maintained at a relatively high level. If the remaining charge of the battery is low, the electrically operated starter cannot start the engine.
A typical watercraft is equipped with a number of power-consuming parts or devices that can be actuated even when the engine is stopped, for example, when the watercraft is anchored at sea. Therefore, it is possible that the remaining charge of the battery will be dissipated without the operator becoming aware that the battery is being almost discharged. For example, when power is consumed for roughly five hours at 7 amperes, the remaining charge of a typical battery can be insufficient to start an engine. A five-hour-power-consumption period is not uncommon on watercraft, especially during offshore fishing activities or when using the watercraft for recreation without the engine running.
One way to prevent an untimely shortage of battery charge is to provide two batteries for the watercraft. One battery is used exclusively for starting the engine, and the other battery is used to provide power to other electrical devices. Some systems use two batteries that are arranged to be switchable to ensure sufficient power to always start the engine. However, in such systems, the batteries can be falsely switched, which may cause a shortage in the charge of the battery that is intended to provide power to start the engine.